zephyr: add gpio interrupts to shim
zephyr: add gpio interrupts to shim

Allow each zephyr project to define the EC_CROS_GPIO_INTERRUPTS item in
their gpio_map.h file to register existing platform/ec gpio irq
handlers.

Unfortunately this cannot go in the device tree file since the device
tree does not support function pointers as a data type.

BRANCH=none
BUG=b:169935802
TEST=hooked up power button GPIO to platform/ec-based gpio irq

Signed-off-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Change-Id: I65d03fed413b270aeae502ad4267b1091582bd91
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2494725
Reviewed-by: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>
Reviewed-by: Simon Glass <c00b0378376498bd9cd974c388df8854c0131d27@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec